Android: Writing file on system partition and use chmod or chown

woff

1. FileOutputStream out = openFileOutput("myfile.test", MODE_WORLD_READABLE);
   
2. File f = getFileStreamPath("myfile.test");
   
3. writeDataToOutputStream(out);
   
4. out.close();
   
5. String filename = f.getAbsolutePath();
   
6. Runtime r = Runtime.getRuntime();
   
7. Process suProcess = r.exec("su");
   
8. DataOutputStream dos = new DataOutputStream(suProcess.getOutputStream());
   
9. dos.writeBytes("chown 0.0 " + filename + "\n");
   
10. dos.flush();
    
11. dos.writeBytes("chmod 644 " + filename + "\n");
    
12. dos.flush();
    
13. dos.writeBytes("mv " + filename + " /system/myfile.test\n");
    
14. dos.flush();

複製代碼

The only thing left (not include din the code above) is to make /system writable. May be one additional command like mount -o rw,remount /system is sufficient - will test that.

在改變檔案權限時，請先r.exec("su");
就能正常執行下面語句